package cuppics;

import org.junit.Test;

public class Prj6 {

	/**
	 * The sum of the squares of the first ten natural numbers is,
	 * 
	 * 12 + 22 + ... + 102 = 385 The square of the sum of the first ten natural
	 * numbers is,
	 * 
	 * (1 + 2 + ... + 10)2 = 552 = 3025 Hence the difference between the sum of
	 * the squares of the first ten natural numbers and the square of the sum is
	 * 3025 − 385 = 2640.
	 * 
	 * Find the difference between the sum of the squares of the first one
	 * hundred natural numbers and the square of the sum.
	 */
	@Test
	public void test() {
		
		System.out.println("diff =" + getDiff(100));
	}
	
	public int getDiff( int num){
		
		return  num * num * ( num + 1) * ( num + 1) / 4 - num * ( num + 1) * ( 2 * num + 1) / 6  ;
		
	}
}
